Amount of Response-produced Change in the Cs and Avoidance Learning.

In discrete-trial avoidance conditioning to an external warning signal, the level of conditioning depended upon how much immediate change in the CS was effected by responding. The greater the change, the better the conditioning; this was interpreted in terms of the amount of reward for avoidance. A 2nd experiment showed that even when the response did not remove the warning signal, the occurrence of an additional, "safety" signal after the response improved level of conditioning. A 3rd experiment showed that a critical variable controlling level of conditioning was the amount of change in the stimulus following the response and that direction of the change, whether toward or away from the between-trials stimulus, was unimportant.